1. Field of the Invention
The present invention relates to a button for attachment to a garment fabric, and more particularly to a button including a tack member having a shank provided with an end portion which is plastically deformable under the influence of a force applied thereto to fit into a button body of the button.
2. Description of the Prior Art
It is known that a metallic button, e.g. a button for blue jeans, is fastened to a garment fabric by a tack member adapted to be joined with a button body of the button. This tack member generally comprises a head and a shank including a deformable tapered end portion. When the tack member is joined with the button body, the shank passes through the garment fabric and then undergoes deformation to some extent upon engagement with the inner wall of the button body.
In one known tack member of this type, the shank has a pointed end portion which is adapted to be bent over in any direction. The major drawback with this prior device is that the bending of the end portion causes an undesired irregular deformation or bend in other portions of the shank and also of the button body, with the result that the button is attached improperly to the fabric in an inclined position.
Another known tack member, disclosed by Japanese Utility Model Publication (Kokoku) No. 44-5791, includes a shank having near its tapered end a transversely extending recess or groove which enables the same to bend easily in one direction about the recess upon engagement of the tack member with the button body. This prior device, however, has a drawback in that the shank has reduced mechanical strength due to removal of the material thereof to form the recess. With this structural weakness of the shank, the tack member would tend to be easily deformed or bent back so as to enable it to be removed from the button body when a relatively great pulling force is exerted on the button. There is also another drawback with this tack member in that the garment fabric positioned around the shank is circumferentially disproportionally dragged into the hollow hub by an irregularly bent portion of the shank other than the tapered end portion during the insertion of the shank to the hollow hub. Thus the garment fabric is apt to pucker so that yarns of the fabric are partially brought into the hollow hub in an irregular manner at different sides of the shank.